Qpsk, Baseband Communication Design And Its Fpga Implementation Of The Study

With the characteristic of multi-speed, multi-mode and intelligence, the modulator-demodulator in a full digital way is suitable for the modern communication system in the future.The main contributions for the full digital modulator- demodulator are as follows:1, Based on the development of the QPSK modulator-demodulator in a full digital way, the discussion of QPSK modulation and demodulation system and the simulation by the EDA software, the system was showed and the devices were chosen for the system.2, After the method being showed for the QPSK modulator-demodulator based on the FPGA, the program being used for the FPGA was designed for the method with VHDL and simulated with the software.3, With the FPGA for QPSK and the devices chosen for the system, the hardware of the system was designed and the hardware of the modulator was accomplished.4, It proved that the data rate is 300Kbps, the center frequency of the IF is 70MHz and the bandwidth is 500kHz. So, the hardware meets the index of the system. The modulation system is finished and the demodulation system is being tested.It proved that the QPSK modulator-demodulator based on FPGA is designed with high integration, great flexibility and upgrade in software. The design in this paper will provide technology for the further design in the modern communication system in the future.